An organic polymer having at least one silicon-containing reactive group is known in the field. This polymer is similar to moisture curable polysiloxane in that it cures by forming siloxane linkage, but is different in that it contains an organic polymer in the backbone chain. One example of such polymer is a polymer of the formula: ##STR3## This polymer can cure by forming siloxane linkage in the presence of moisture.
The organic polymer having at least one silicon-containing reactive group can be used as a pressure sensitive adhesive and a sealant (of. U.S. Pat. Nos. 4,463,115 and 3,971,751).
Usually, a curing catalyst is used for curing the organic polymer having at least one silicon-containing reactive group. As the curing catalyst, there are known various compounds such as titanate esters (e.g. tetra-n-butoxytitanate), tin carboxylate compounds (e.g. dibutyltin dilaurate and tin dioctylate) and amines. Although these catalysts are selected and used according to the final use and application of the curable composition, generally they have low catalytic activity and only provide a low curing rate. Therefore, a highly active curing catalyst which can cure the composition at a high rate is desired.
In the case where the polymer is used as the pressure sensitive adhesive, the polymer is required to cure in a very short period of time, i.e., within one minute, for effective production of the adhesive. Among the curing catalysts described above, titanate esters and a combination of tin carboxylate and amine have fairly high curing activity. However, the pressure sensitive adhesive containing titanate ester has drawbacks such as discoloring of the adhesive. The pressure sensitive adhesive containing tin carboxylate and amine has drawbacks such as discoloring and odor due to amine, and bleeding of amine on the surface of the pressure sensitive adhesive which results in change of adhesive properties.
In the case where the polymer is used as the sealant, the curing catalyst having high activity is required for shorter term of works. The sealant composition containing tin carboxylate and amine has high curing rate, but has low adhesivity to a substrate which is one of the important properties of the sealant. Moreover, the sealant composition containing tin carboxylate has such a drawback that the activity of the catalyst is decreased after the storage of the composition.